Adaptive Multi-Rate Wideband (AMR-WB) is a patented wideband speech audio coding standard developed based on Adaptive Multi-Rate encoding, using a similar methodology to algebraic code-excited linear prediction (ACELP).
The lowest bit rate providing excellent speech quality in a clean environment is 12.65 kbit/s.
(For Tandem Free Operation interoperability with GSM/GERAN, mode change rate is restricted in 3G to 40 ms in AMR-WB encoders.)"
All other bitrates can still be used for other purposes in mobile phone networks, including multimedia messaging, streaming audio, etc.
AMR-WB has been standardized by a mobile phone manufacturer consortium for future usage in networks such as UMTS.
[citation needed] In October 2006, the first AMR-WB tests were conducted in a deployed network by T-Mobile in Germany, in cooperation with Ericsson.
[10][11] In 2007 an end-to-end AMR-WB TrFO capable 3G & VoIP product line was commercially released by NSN (M13.6 MSS, U3C MGW).
WIND Mobile also announced that several handsets will support HD Voice (AMR-WB) in the first half of 2011,[14] with the first one being Alcatel Tribe.